Input and output device and terminal device for inputting data with sensation of handwriting

ABSTRACT

A lenticular lens is provided in front of a liquid crystal panel composed of a plurality of pixels. In this case, the lenticular lens is arranged so that one cylindrical lens corresponds to two pixels adjacent to each other. Then, light rays outgoing from two pixels are refracted by this one cylindrical lens and intersect with each other at a point positioned on the surface of a tablet, and then reach the right eye and the left eye of a user, respectively.

This is a continuation of application Ser. No. 11/154,734 filed Jun. 17,2005, which claims priority from Japanese Application No. 2004-181863filed Jun. 18, 2004. The entire disclosures of the prior applicationsare considered part of the disclosure of the accompanying continuationapplication and are hereby incorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an input and output device whichincludes a flat input unit mounted on a display unit, and inputs whiledisplaying characters and figures inputted by handwriting into the flatinput unit in real time, and a terminal device using this. Particularly,the present invention can be preferably applicable to input and outputdevices which are equipped with terminal devices such as cell phones,mobile terminals, PDAs (personal digital assistances), game machines,digital cameras, digital video cameras, and personal computers, and caninput data with sensation of handwriting, and terminal devices includingthe input and output devices.

2. Description of the Related Art

As means for inputting data into a computer, keyboards are generallyknown. However, at present, data to be inputted into computers is notonly text data composed of arrangement of the alphabet and numeralsassigned to a keyboard, but also data to be inputted in a way likehandwriting of characters and figures on a paper with a pen. As meansfor inputting information while looking at a display screen, a mouse,tablets, and touch panels have already been made practicable. However,among these, a mouse is used by users for input operation from positionsapart from the display screen, so that the sensation like drawingcharacters and figures with a pen cannot be obtained.

On the other hand, in the case of an input and output device having atablet and a touch panel (hereinafter, called a tablet as a general termof these) overlapped on a flat panel display such as a liquid crystaldisplay (hereinafter, referred to as LCD also), a user can inputinformation only by bringing the tip end of an input pen or his/herfingertip close to the display screen, and the inputted data isdisplayed on the flat display panel in real time. Therefore, by usingsuch an input and output device, the sensation like handwriting ofcharacters and figures on a paper with a pen is obtained, so that thisdevice is used for supporting users to input data into computers.

FIG. 1 is a sectional view showing a conventional input and outputdevice. As shown in FIG. 1, this conventional input and output deviceincludes an LCD 51, a tablet 52 overlapped on this LCD 51, and a pen 53for inputting data into this tablet 52. In the LCD 51 a TFT substrate 48on which, for example, data bus lines, gate bus lines, pixel electrodesand thin film transistors (hereinafter, referred to as TFT) are formedand a color filter substrate 49 on which transparent electrodes made ofITO (indium tin oxide) and color filters are formed are provided inparallel to each other, and between the TFT substrate 48 and the colorfilter substrate 49, a liquid crystal layer 50 is disposed. For example,the TFT substrate 48 and the color filter 49 are glass substrates withthicknesses of approximately 0.5 mm, and in the tablet 52, a film withtransparent electrodes made of ITO or the like is laminated and fixed toa supporting substrate, and the thickness of this supporting substrateis approximately 1 mm.

However, the above-described conventional technique has the followingproblem. As shown in FIG. 1, it is assumed that the tip end of the pen53 is made contact with the point A of the tablet 52 for inputting imagedata by a user. In this case, the tablet 52 detects the contact of thepen 53 and outputs the contact position data to the LCD 51, and based onthis position data, the LCD 51 displays at the point B corresponding tothe position. At this point, as shown in FIG. 1, the point A and thepoint B are at a distance corresponding to the total thickness of thetablet 52 and the color filter substrate 49 of the LCD 51 from eachother. For example, in the case of this input and output device, thethickness of the tablet 52 is 1 mm, the thickness of the color filtersubstrate 49 of the LCD 51 is 0.5 mm, so that the point A and the pointB are at a 1.5 mm distance in total from each other. Therefore, when auser looks at these points, the image looks deep and the user has asense of discomfort. Due to this “depth feel,” the input operation ofthe user loses accuracy, and the operation efficiency significantlylowers and makes the user tired.

In order to solve this problem, the following method has been proposed.For example, Japanese Patent Publication No. H4-114224 discloses atechnique for reducing the depth feel by using optical fibers. FIG. 2 isa perspective view showing the conventional input and output devicedisclosed in Japanese Patent Publication No. H4-114224, and FIG. 3 is aschematic sectional view of the identical. As shown in FIG. 2 and FIG.3, in this conventional input and output device, an illumination backlight 58 is provided, and in front of this back light 58, a flat display57 is disposed. The flat display 57 is a liquid crystal display, whereintwo substrates are disposed in parallel to each other, and betweenthese, a liquid crystal layer (not shown) is disposed. In addition, infront of the flat display 57, a parallax correcting plate 56 formed bybundling optical fibers into a plate shape is provided, and in front ofthe parallax correcting plate 56, a tablet 55 is provided. The tablet 55detects a contact position of a pen 54 when the pen 54 comes intocontact with it. In FIG. 3, a path 59 of light emitted from the backlight 58 is shown.

As shown in FIG. 3, the substrate thickness on the user side of the flatdisplay 57 is defined as d1, and the thickness of the tablet 55 isdefined as d2. If no parallax correcting plate 56 is provided, thedisplay position on the flat display 57 viewed from a user is the pointC positioned on the liquid crystal layer. Therefore, when the pen 54 ismade contact with the tablet 55, there is a distance of (d1+d2) betweenthe contact point E of the pen 54 on the surface of the tablet 55 andthe display point C on the flat display 57. On the other hand, when theparallax correcting plate 56 is inserted between the flat display 57 andthe tablet 55, light that has been emitted from the back light 58 andtransmitted through the display 57 is transmitted along the path 59 inthe optical fibers of the parallax correcting plate 56, and is imaged atthe point D. Thereby, the distance between the display position (pointD) and the input position (point E) becomes d2, whereby the depth feelcan be reduced in comparison with the case where no parallax correctingplate 56 is provided.

In addition, for example, Japanese Patent Publication No. H10-283114discloses a technique for forming an image on the surface of an inputand output device by using a micro lens and a light diffusion layer.FIG. 4 is a schematic sectional view showing the conventional input andoutput device disclosed in Japanese Patent Publication No. H10-283114.As shown in FIG. 4, in this input and output device, an electromagneticexchange type sensor substrate 63 is provided, and in front of thissensor substrate 63, a back light 64, a liquid crystal display unit 65,a micro lens array sheet 69, and a light diffusion layer 70 are providedin this order. In the liquid crystal display unit 65, a liquid crystallayer 68 is disposed between an upper substrate 66 and a lower substrate67. In addition, in the micro lens array sheet 69, a number of lensesare formed on the upper substrate 66 side. Furthermore, the lightdiffusion layer 70 diffuses light converged by the micro lens arraysheet 69. The sensor substrate 63 detects the position of the tip end ofthe pen 71 by means of the electromagnetic exchange method.

When the micro lens array sheet 69 and the light diffusion layer 70 arenot provided, light transmitted through the point A of the liquidcrystal display unit 65 appears to have exited from the point A.Therefore, even when the user tries to make the tip end of the pen 71contact with the point A from above, the point A and the tip end of thepen 71 deviate from each other at a distance corresponding to thethickness of the upper substrate 66. On the other hand, by providing themicro lens array sheet 69 and the light diffusion layer 70, light thathas exited from the point A is converged to the light diffusion layer 70by lenses formed on the micro lens array sheet 69, and imaged at thepoint B on the light diffusion layer 70. Thereby, when a user looks atthis, the image appears to be displayed at the point on the lightdiffusion layer 70, whereby the depth feel due to the thickness of theupper substrate 66 can be reduced.

However, the conventional technique has the following problem. With thetechnique described in Japanese Patent Publication No. H4-114224 shownin FIG. 2 and FIG. 3, the depth feel due to the thickness d2 of thetablet 55 cannot be corrected even by using the parallax correctingplate 56. In addition, since the parallax correcting plate 56 ismanufactured by bundling and binding the optical fibers with a resin, itis difficult to manufacture a large-size parallax correcting plate.Furthermore, the number of optical fibers to be bundled increases inproportion to the area, and therefore, to manufacture a plate with acomparatively large area such as a monitor for a cell phone, a PDA, or amonitor of a personal computer, a large number of fibers must bebundled, and the costs are extremely high.

In addition, the technique described in Japanese Patent Publication No.H10-283114 shown in FIG. 4 employs a method in which an image is formedon the surface of the input and output device by using lenses, so thatlight must be scattered on the surface of the input and output device bythe light diffusion layer 70. However, the light diffusion layer 70scatters not only the light emitted from the liquid crystal display unit65 but also externally entering light. Therefore, the contrast of thedisplay unit is significantly lowered, and this lowers the operationefficiency of a user. In addition, since light of the image to bedisplayed is scattered, for example, when a character is displayed, thecharacter becomes blurred or thicker more than the actual image. Thisuse of the light diffusion layer lowers the display quality.

SUMMARY OF THE INVENTION

An object of the present invention is to provide an input and outputdevice which can reduce the depth feel of an image and realizes highdisplay quality at low costs, and a terminal device including the inputand output device.

The input and output device according to the present inventioncomprises: a display unit including pixel groups composed of a pluralityof pixels aligned in a matrix; an optical member which turns lightoutgoing from a first pixel among the pixels belonging to each of thepixel groups toward a first direction and turns light outgoing from asecond pixel among the pixels belonging to each of the pixel groupstoward a second direction, and a locus of a first light outgoing fromthe first pixel and a locus of a second light outgoing from the secondpixel which are driven by the same signal intersect with each other; anda flat input unit which is disposed in front of the display unit andtransmits light outgoing from the display unit and detects thecoordinates of a contact point when it is contacted from the front side.

In the invention, since the loci of light outgoing from the first andsecond pixels driven based on the identical signal intersect with eachother, light outgoing from the first pixel is made to reach the righteye of a user, and the light outgoing from the second pixel is made toreach the left eye of the user, whereby the user is made to recognizethe light outgoing from the first and second pixels as light outgoingfrom the intersection so as to recognize the image displayed by thedisplay unit as being displayed on a virtual plane composed of a set ofintersections. Thereby, the depth feel of the image can be reduced. Inthe invention, since no special parts are used, the costs are low, andthe display quality is high since light is not diffused, and it is notnecessary to form an image on a screen or the like.

It is preferable that the locus of the first light and the locus of thesecond light intersect with each other on the front face of the flatinput unit. Thereby, the above-mentioned virtual display surface can bematched with the front face of the flat input unit, whereby the depthfeel is eliminated.

In the case of arrangement in which light outgoing from the first pixelreaches the right eye of the user and light outgoing from the secondpixel reaches the left eye of the user, when the interval between theeyes of the user is defined as W, the aligning pitch of the pixels inthe direction of distributing light by the optical member is defined asP, the distance from the display surface of the display unit to thefront face of the flat input unit is defined as T, the distance from thefront face of the flat input unit to the eyes of the user is defined asL, and an integer equal to or more zero are defined as n, it ispreferable that the formula (W:L=P×(2n+1):T) is satisfied. Thereby, theabove-mentioned virtual display surface can be matched with the frontface of the flat input unit, whereby the depth feel can be eliminated.

Furthermore, the optical member may be a lenticular lens. Thereby, theoptical member can be formed by a simple lens system, and this reducesthe costs.

Another input and output device of the present invention comprises: alight source for alternately emitting light in a first direction and asecond direction; a liquid crystal panel that is disposed in front ofthe light source and includes a plurality of pixels; and a flat inputunit that is disposed in front of the liquid crystal panel and transmitslight outgoing from the liquid crystal panel and detects the coordinatesof a contact position when it is contacted from the front side. When thelight source emits light in the first direction, a first pixel of theliquid crystal panel which is driven by one signal transmits a light raypassing through a point of the front face of the flat input unit, andwhen the light source emits light in the second direction, a secondpixel of the liquid crystal panel which is driven by the same signal asthe one signal transmits a light ray passing through the point of thefront face of the flat input unit.

In the invention, the first and second pixels can be driven by a timedivision system. Thereby, an optical member for distributing the lightbecomes unnecessary.

The terminal device according to the present invention has the input andoutput device.

The terminal device according to the present invention may be a cellphone, a PDA, a mobile terminal, a game machine, a digital camera, or adigital video camera.

According to the invention, since the loci of light outgoing from thefirst and second pixels driven based on the identical signal intersectwith each other, a user can be made to recognize a virtual displaysurface on a plane positioned ahead of the actual display surface of thedisplay unit, whereby the depth feel of the image can be reduced. Inaddition, the input and output device of the invention does not needspecial parts, so that costs are low, and the display quality is highsince light is not diffused.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a sectional view showing a conventional input and outputdevice;

FIG. 2 is a perspective view showing a conventional input and outputdevice disclosed in Japanese Patent Publication No. H4-114224;

FIG. 3 is a schematic sectional view showing the input and output deviceshown in FIG. 2;

FIG. 4 is a schematic sectional view showing a conventional input andoutput device disclosed in Japanese Patent Publication No. H10-283114;

FIG. 5 is a perspective view showing an input and output deviceaccording to a first embodiment of the present invention;

FIG. 6 is a partial sectional view showing the input and output deviceshown in FIG. 5;

FIG. 7 is a diagram showing the optical construction of the input andoutput device shown in FIG. 5;

FIG. 8 is a drawing showing pixels and lenses of an input and outputdevice according to a modified example of the first embodiment;

FIG. 9 is a diagram showing an optical construction of an input andoutput device according to a second embodiment of the present invention;

FIG. 10 is a diagram generally showing the optical construction of theinput and output device according to the embodiment;

FIG. 11 is a plan view showing a liquid crystal panel in a thirdembodiment of the present invention;

FIG. 12 is a view showing pixels and lenses of the input and outputdevice of the embodiment; and

FIG. 13 is a diagram showing an optical construction of an input andoutput device according to a fourth embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereinafter, embodiments of the present invention are described indetail with reference to the accompanying drawings. First, a firstembodiment of the invention is described. FIG. 5 is a perspective viewshowing an input and output device of this embodiment, FIG. 6 is apartial sectional view of the identical, and FIG. 7 is a diagram showingthe optical construction thereof. The input and output device of thisembodiment is an input and output device mounted in a PDA.

As shown in FIG. 5, in the input and output device 1 of this embodiment,a liquid crystal display unit 3 as an output unit is provided, and atablet 2 as an input unit is provided in front of this liquid crystaldisplay unit 3. In front of the tablet 2, an input/output region 5 isprovided. In response to pressing of the input/output region 5 with apen 4 as an input means by a user, data is inputted into the tablet 2.The entirety of the tablet 2 transmits light, and the user can view animage displayed by the liquid crystal display unit 3 in the region 5. Inaddition, a control unit (not shown) which receives an input of datafrom the tablet 2, processes the inputted data, and outputs it to theliquid crystal display unit 3 is provided.

In addition, as shown in FIG. 6, in the liquid crystal display unit 3, aback light 8 is provided, and in front of the back light 8, a liquidcrystal panel 3 a is provided. In the liquid crystal panel 3 a, a TFTsubstrate 7 as a back face substrate, a color filter substrate 6 as afront face substrate disposed opposite the TFT substrate 7 in front ofthe TFT substrate 7, and a liquid crystal layer 12 disposed between theTFT substrate 7 and the color filter substrate 6 are provided, and onthe front face of the color filter substrate 6 and the back face of theTFT substrate 7, polarizing films 10 and 11 are affixed, respectively.Between the liquid crystal display unit 3 and the tablet 2, a lens 9 isprovided which distributes a light ray outgoing from the liquid crystaldisplay unit 3 into a plurality of directions. The lens 9 is alenticular lens including, for example, a plurality of cylindricallenses 9 a aligned in parallel to each other.

Furthermore, as shown in FIG. 7, in the liquid crystal panel 3 a, aplurality of pixels are provided. In FIG. 7, for convenience, only sixpixels 15 through 20 are shown, however, in actuality, more pixels areprovided in the liquid crystal panel 3 a. In FIG. 7, the color filtersubstrate 6, the TFT substrate 7, the polarizing sheets 10 and 11, andthe back light 8 are omitted. Each cylindrical lens 9 a of the lens 9corresponds to pixels in two rows aligned in the longitudinal directionof the cylindrical lens 9 a. For example, one cylindrical lens 9 acorresponds to two pixels 16 and 19 adjacent to each other. Light raysoutgoing from the pixels 16 and 19 are refracted and converged by thiscylindrical lens 9 a, intersect with each other at the point Fpositioned on the surface of the tablet 2, and then reach the right eye13 and the left eye 14 of a user, respectively.

Therefore, when the interval between the eyes of the user is defined asW, the aligning pitch of the pixels in the aligning direction of thecylindrical lenses 9 a is defined as P1, the distance from the interfacebetween the liquid crystal layer 12 (see FIG. 6) and the color filtersubstrate 6 (see FIG. 6) in the liquid crystal panel 3 a to the frontface of the tablet 2 is defined as T1, and the distance between thefront face of the tablet 2 and the right eye 13 and the left eye 14 ofthe user is defined as L1, the following formula 1 is satisfied.W1:L1=P1:T1  (Formula 1)

Next, operations of the input and output device of this embodimentconstructed as mentioned above are described. When a user makes the tipend of the pen 4 contact with the input/output region 5 of the tablet 2,the tablet 2 detects the position of the tip end of the pen 4 ascoordinate data on a two dimensional plane, and outputs this coordinatedata to the control unit (not shown). The control unit processes andstores this coordinate data and then outputs this to the liquid crystaldisplay unit 3. Then, the liquid crystal display unit 3 displays apredetermined mark (for example, black point) in real time atcoordinates on the liquid crystal panel 3 a corresponding to thecoordinates of the tip end of the pen 4 based on the coordinate data. Inthis case, the control unit successively stores the coordinate datainputted in the tablet 2, whereby figures such as lines can be inputtedand displayed on the liquid crystal display unit 3.

In this case, the liquid crystal display unit 3 makes a pixel groupcomposed of a plurality of pixels at the relatively identical positionas each cylindrical lens 9 a of the lens 9 to display one image, andalso makes another pixel group at an another position relative to eachcylindrical lens 9 a to display the image. Namely, the pixel groupcomposed of the pixels 15, 16, and 17 is made to display an image, andanother pixel group composed of the pixels 18, 19, and 20 is also madeto display the image. Therefore, a pair of pixels corresponding to onecylindrical lens 9 a of the lens 9, for example, the pixels 16 and 19are driven by the identical signal, the pixels 15 and 18 are driven byanother identical signal, and the pixels 17 and 20 are driven by stillanother identical signal.

In this state, the back light 8 emits light, and this light istransmitted through the pixels of the liquid crystal panel 3 a andenters the lens 9. At this point, light rays transmitted through, forexample, pixels 16 and 19 are refracted and converged by one cylindricallens 9 a of the lens 9 and intersect with each other at the point Fpositioned on the front face of the tablet 2, and the light transmittedthrough the pixel 16 reaches the right eye 13 of the user, and the lighttransmitted through the pixel 19 reaches the left eye 14 of the user.Likewise, light rays transmitted through the pixels 15 and 18 intersectwith each other at another point (not shown) positioned on the frontface of the tablet 2 and reach the right eye 13 and the left eye 14,respectively. Light rays transmitted through the pixels 17 and 20intersect with each other at still another point (not shown) positionedon the front face of the tablet 2 and reach the right eye 13 and theleft eye 14, respectively. Namely, the pixels 15, 16, and 17 display animage for the right eye, and the pixels 18, 19, and 20 display an imagefor the left eye. The image for the right eye and the image for the lefteye are identical to each other, however, their display position on theliquid crystal panel 3 a deviate a distance of one pixel from eachother.

Thereby, a user views the image for the right eye displayed by thepixels 15, 16, and 17 with the right eye 13, and views the image for theleft eye displayed by the pixels 18, 19, and 20 with the left eye 14,however, for the user, the light transmitted through the pixel 16 andthe light transmitted through the pixel 19 appear to have exited fromthe identical point F (not shown) positioned on the front face of thetablet 2. Likewise, the light transmitted through the pixel 15 and thelight transmitted through the pixel 18 also appear to have exited fromanother identical point (not shown) positioned on the front face of thetablet 2, and the light transmitted through the pixel 17 and lighttransmitted through the pixel 20 also appear to have exited from stillanother identical point (not sown) positioned on the front face of thetablet 2. The identical applies to other pixel pairs that are not shownin FIG. 7. As a result, for the user, the image appears to be displayedon the front face of the tablet 2.

It is allowed that the background of the input/output region 5 is set tobe plain (for example, white entirely), and only data inputted by a userwith the pen 4 is displayed, or some image is displayed in advance, anda user writes over this image while viewing it.

Next, the effects of the invention are described. As described above, inthis embodiment, an image for the right eye is displayed by one pixelgroup and supplied to the right eye of a user, and an image for the lefteye is displayed by another pixel group and supplied to the left eye ofthe user. Then, a light ray for displaying each point of the image forthe right eye and a light ray for displaying each point of the image forthe left eye intersect with each other. Thereby, for the user, two lightrays for displaying points corresponding to each other on the image forthe right eye and the image for the left eye appear to have exited fromthe intersection, and a user recognizes a plane formed of a set of theintersections as a virtual display surface. Then, this virtual displaysurface is matched with the surface of the input and output device,whereby the depth feel of the image can be eliminated. Thereby, inputoperations by the user are made easy and the input accuracy andefficiency are improved. The input and output device of this embodimentdoes not need to use expensive parts such as optical fibers, so thatcosts are low. Furthermore, it is not necessary to form an image on ascreen or the like, so that light is not diffused and display quality isnot lowered.

In FIG. 7, paths of light transmitted through the pixels are shown bylines, however, in an actual display unit, each pixel has a fixeddefinite area, and light emitted therefrom is also outputted in variousdirections. Therefore, the position to be supplied with the image forthe right eye and the position to be supplied with the image for theleft eye in front of the input and output device 1 do not exist on oneline each, but exist as a spatial region having a fixed angle of vieweach. Therefore, when a user positions his/her right eye 13 and left eye14 in the respective spatial regions, he/she can recognize the virtualdisplay surface. Therefore, the viewpoint for eliminating the depth feelis not the one point of FIG. 7.

Next, a modified example of this first embodiment is described. FIG. 8shows pixels and a lens of an input and output device of this modifiedexample. As shown in FIG. 8, in the modified example, six pixels 21through 26 correspond to one cylindrical lens 9 b of the lens 9. Lightrays transmitted through the pixels 21 through 26 are refracted andconverged by the lenticular lens 9 b, and intersect with each other atone point, and then outgo in different directions. Thereby,multi-viewpoint display is realized. The image for the right eye isdisplayed by one pixel of the pixels 21 through 26, and the image forthe left eye is displayed by another one pixel, whereby the identicaleffects as in the first embodiment are obtained. In addition, forexample, the pixels 21, 23, and 25 display an identical image for theleft eye and the pixels 22, 24, and 26 display an identical image forthe right eye, whereby a user can extend the position at which he/shecan recognize the virtual display surface. The construction, workings,and effects of this modified example other than these are the identicalas those of the first embodiment.

Next, a second embodiment of the invention is described. FIG. 9 showsthe optical construction of an input and output device of thisembodiment. As shown in FIG. 9, in this embodiment, the dimensions ofthe parts are different from those of the first embodiment. Namely, whenthe interval between the eyes of a user is defined as W, the aligningpitch of the pixels in the direction of aligning the cylindrical lenses9 a is defined as P1, the distance from the interface between the liquidcrystal layer 12 (see FIG. 6) and the color filter substrate 6 (see FIG.6) of the liquid crystal panel 3 a to the front face of the tablet 2 isdefined as T1, and the distance between the front face of the tablet 2and the right eye 13 and left eye 14 of the user is defined as L2, thefollowing formula 2 is approximately satisfied. The construction of thisembodiment other than these is the identical as that of the firstembodiment.W:L2=P1×3:T2  (Formula 2)

Next, workings of this embodiment are described. In this embodiment, inthe liquid crystal panel 3 a, a pair of pixels positioned apart fromeach other via two pixels along the direction of aligning thecylindrical lenses 9 a display identical images for the right eye andfor the left eye, respectively. For example, the pixel 16 shown in FIG.9 displays the image for the right eye, and the pixel 18 displays theimage for the left eye corresponding to this image for the right eye.Namely, the pixels 16 and 18 are driven by an identical signal. Then, alight ray transmitted through the pixel 16 and a light ray transmittedthrough the pixel 18 enter the cylindrical lenses 9 a adjacent to eachother, and are refracted by these cylindrical lenses 9 a, intersect witheach other at the point G positioned on the front face of the tablet 2,and the light transmitted through the pixel 16 reaches the right eye 13of the user and the light transmitted through the pixel 18 reaches theleft eye 14 of the user. Likewise, when the pixels 17 and 19 display animage for the right eye and an image for the left eye corresponding toeach other, the light rays transmitted through the pixels 17 and 19 arerefracted by two cylindrical lenses 9 a adjacent to each other,intersect with each other at another point (not shown) on the front faceof the tablet 2, and reaches the right eye 13 and the left eye 14,respectively. Workings other than these in this embodiment are theidentical as those of the first embodiment.

Next, effects of this embodiment are described. As described above, apair of pixels 16 and 18 apart from each other via two pixels display animage for the right eye and an image for the left eye corresponding toeach other, and two light rays transmitted through these two pixelsintersect with each other at the point G positioned on the front face ofthe tablet 2, and reach the right eye 13 and the left eye 14 of theuser, respectively, whereby for the user, the two light rays appear tohave exited from the point G. Therefore, the user can recognize avirtual display surface on the front face of the tablet 2, whereby thedepth feel of the image can be eliminated. In this embodiment, thethickness of the tablet 2 can be increased more than in the firstembodiment. Other effects of this embodiment are the identical as thoseof the first embodiment.

In the first embodiment, left and right images corresponding to eachother are displayed by a pair of pixels adjacent to each other, and inthe second embodiment, left and right images corresponding to each otherare displayed by a pair of pixels disposed via two pixels therebetween,however, the positional relationship of the pair of pixels fordisplaying the left and right images corresponding to each other is notlimited to the examples of the first and second embodiments. FIG. 10generally shows the optical construction of an input and output deviceof this embodiment. As shown in FIG. 10, the relationship between thepositional relationship of the pair of pixels and the dimensions of theparts in the input and output device are generally expressed as follows.Namely, when the number of pixels to be sandwiched by the pair of pixelsis defined as 2n (n is an integer of 0 or more), the following formula 3is approximately satisfied. The first embodiment is in the case where nequals zero in the following formula 3, and the second embodiment is inthe case where n equals 1.W:L2=P1×(2n+1):T2  (Formula 3)

As shown in the formula 3, an input and output device can be providedwhich reduces the depth feel even when the surfaces of the liquidcrystal panel and the tablet 2 are changed, that is, the distance to theposition in contact with the tip of the pen is changed. The reason forthis is that the pixel for displaying the image for the right eye andthe pixel for displaying the image for the left eye can be selected byselecting the value of n, and thereby, the distance between the point Gand the liquid crystal panel 3 a can be adjusted by the distance betweenthe two selected pixels.

Next, a third embodiment of the invention is described. FIG. 11 is aplan view showing a liquid crystal panel 3 a of this embodiment, andFIG. 12 shows pixels and a lens of an input and output device of thisembodiment. The input and output device of this embodiment is installedin a cell phone. In the input and output device of this embodiment, thepositional relationship between the tablet 2 and the liquid crystaldisplay unit 3 and the positional relationship of the components in theliquid crystal display unit 3 are the identical as those of the inputand output device of the first embodiment shown in FIG. 5 and FIG. 6.Hereinafter, the construction of this embodiment is described withreference to FIG. 5 and FIG. 6.

In this embodiment, the liquid crystal panel 3 a of the liquid crystaldisplay unit 3 has a diagonal screen size of 4 inches, and has a pixelnumber of 480 pixels (picture elements) vertically and 320 pixelshorizontally. The tablet 2 is a resist film tablet using ITO fortransparent electrodes. The input and output device of this embodimentis used in a mobile terminal. Furthermore, the back light 8 is a backlight using light emitting diodes. The TFT substrate 7 applies a signalvoltage for controlling the orientation of the liquid crystal layer 12to the liquid crystal layer 12. The lens 9 is a lenticular lens made ofan acrylic resin, and the height of each cylindrical lens 9 a is, forexample, 10 micrometers. The distance from the interface between theliquid crystal layer 12 and the color filter substrate 6 to the frontface of the tablet 2, that is, the distance to the surface on the sideto be contacted with the pen 4 is, for example, 1.6 mm.

In addition, as shown in FIG. 11, in the liquid crystal panel 3 a, aplurality of picture elements (pixels) 41 are aligned in a matrix. Ineach picture element 41, six pixels 42 through 47 are aligned in amatrix of 3 lines and 2 rows. Namely, in each picture element 41, pixels42, 44, and 46 are aligned in a row in this order along the linedirection, and the pixels 43, 45, and 47 are aligned in a row in thisorder along the line direction. In addition, the pixels 42 and 43, thepixels 44 and 45, and the pixels 46 and 47 are aligned along the rowdirection, respectively. One picture element 41 is composed of threecolor pixels of R, G, and B, and the pixels 42 and 43 are red (R)pixels, the pixels 44, and 45 are green (G) pixels, and the pixels 46and 47 are blue (B) pixels. In addition, the pixels 42, 44, and 46 arepixels for the right eye for displaying an image for the right eye, andthe pixels 43, 45, and 47 are pixels for the left eye for displaying animage for the left eye.

This picture element 41 composed of a set of six pixels are arranged 480vertically and 320 horizontally to form a display part. As shown in FIG.12, cylindrical lenses 9 a of the lens 9 extend in the line direction,that is, the vertical direction of the liquid crystal panel 3 a, and onecylindrical lens 9 a corresponds to the row of picture elements 41aligned in a row in the line direction. Namely, the width of onecylindrical lens 9 a equals the width of the picture element 41.

Next, working of this embodiment is described with reference to FIG. 9.In this embodiment, the interval between the eyes of the user, that is,the distance W between the right eye 13 and the left eye 14 is set to 65mm, and the distance L2 between the right eye 13 and left eye 14 and thesurface of the input and output device 1 is set to 400 mm. In addition,as described above, the distance from the interface between the liquidcrystal layer 12 and the color filter substrate 6 to the front face ofthe tablet 2 is set to 1.6 mm. When the distance between a pair ofpixels for displaying an image for the right eye and an image for theleft eye corresponding to each other is defined as X, the followingformula 4 is satisfied from the formula 3. Namely, by determining thedistance X so as to satisfy the following formula 4, display in whichthe depth feel is eliminated is realized.65:400=X:1.6  (Formula 4)

From the formula 4, X=0.26 mm. Then, the diagonal screen size of theliquid crystal panel 3 a is 4 inches, and the number of picture elementsis 480 vertically and 320 horizontally, so that the aligning pitch ofthe picture elements is 177 micrometers. Therefore, as shown in FIG. 12,the aligning pitch P of the pixels is the half of the aligning pitch ofthe picture elements, so that P=88.5 micrometers. Therefore, the cyclenumber N of the pixels corresponding to the distance X is determined bythe following formula 5.N=X÷P=0.26÷0.0885≅3  (Formula 5)

From the formula 5, in this embodiment, a pair of pixels disposed at adistance three times the aligning pitch P of the pixels from each otherare made to display an image for the right eye and an image for the lefteye corresponding to each other, whereby a user can be made to recognizea virtual display surface almost on the surface of the input and outputdevice, that is, the front face of the tablet 2, and the depth feel canbe almost completely eliminated. This means that, as shown in FIG. 9,the pixels 16 and 18 disposed by sandwiching two pixels therebetween aremade to display an image for the right eye and an image for the left eyecorresponding to each other. Other workings and effects of thisembodiment are the identical as those of the second embodiment.

Next, a fourth embodiment of the invention is described. FIG. 13 showsan optical construction of an input and output device of thisembodiment. This embodiment is different from the third embodiment inthat a pair of pixels adjacent to each other display an image for theright eye and an image for the left eye corresponding to each other andthe distance from the interface between the liquid crystal layer 12 andthe color filter substrate 6 to the front face of the tablet 2 is 0.7mm. The construction other than these is the identical as that of thethird embodiment. Namely, the positional relationship between the tablet2 and the liquid crystal display unit 3 and the positional relationshipof the components of the liquid crystal display unit 3 are the identicalas those of the input and output device of the first embodiment shown inFIG. 5 and FIG. 6, and the tablet 2 is a resist film tablet, thediagonal screen size of the liquid crystal panel 3 a is 4 inches, andthe pixel number is 480 picture elements vertically and 320 pictureelements horizontally, and the alignment of the pixels 42 through 47 ineach picture element 41 is as shown in FIG. 12, and the height of thecylindrical lenses 9 a is 10 micrometers.

As shown in FIG. 13, the distance between the eyes of a user is set to65 mm, the distance L3 between the right eye 13 and left eye 14 and thesurface of the input and output device 1 is set to 400 mm. In addition,as described above, the distance T3 from the interface between theliquid crystal layer 12 and the color filter substrate 6 to the frontface of the tablet 2 is set to 0.7 mm. Furthermore, the intersection oflight rays transmitted through a pair of pixels adjacent to each other,for example, the pixels 16 and 19 shown in FIG. 13 is defined as a pointH, the distance from the interface between the liquid crystal layer 12and the color filter substrate 6 to the intersection H is defined as T4,and the distance from the intersection H to the right eye 13 and lefteye 14 of the user is defined as L4. Furthermore, as in the case of thethird embodiment, the aligning pitch of the picture elements 41 (seeFIG. 12) is 177 micrometers, and the aligning pitch P of pixels is 88.5micrometers. Thereby, the following formulas 6 and 7 are satisfied fromFIG. 13.L4+T4=L3+T3=400+0.7  (Formula 6)65:L4=0.0885:T4  (Formula 7)

The distances L4 and T4 calculated from the formulas 6 and 7 areL4≈400.155 mm and T4≈0.545 mm. The distance T3 is 0.7 mm and thedistance T4 is 0.545 mm, so that the difference between T3 and T4 is0.155 mm.

Therefore, although the distance between the display point J of theliquid crystal panel 3 a and the contact point I with the pen 4 isapproximately 0.7 mm in the conventional input and output device, inthis embodiment, the distance between the vertical display point H andthe contact point I with the pen 4 is 0.155 mm. Therefore, in comparisonwith the conventional input and output device, the input and outputdevice of this embodiment can significantly reduce the depth feel. Theworkings and effects other than these in this embodiment are theidentical as those of the third embodiment.

In the third and fourth embodiments, a resist film type is used for thetablet 2 and position detection is carried out in response to contactwith the pen 4, however, the invention is not limited to this, and anelectrostatic capacitory coupling tablet may be used, and the identicaleffects as those of the third and fourth embodiments can be obtainedeven by using any other type of tablet that is used by being disposedbetween the display unit and a user.

In the above-mentioned embodiments, the tablet 2 is disposed between theliquid crystal display unit 3 and a user, however, the invention is notlimited thereto, and it is allowed that the tablet is disposed on theback face of the display unit as long as inputting is possible. Forexample, even when an electromagnetic induction type tablet is disposedon the back face of the liquid crystal display unit 3 and the positionof the tip end of the pen is detected, the identical effects as those ofthe third and fourth embodiments are obtained. In this case, only thedepth feel caused by the front face substrate of the liquid crystalpanel is eliminated. In the liquid crystal display panel 3 a, there isno special limitation on the hierarchical relationship of the colorfilter substrate 6 and the TFT substrate 7.

Furthermore, in the embodiments described above, the output equipment isa liquid crystal display unit, however, the invention is not limitedthereto, and a display unit other than the liquid crystal display unit,for example, an organic EL display, a plasma display, etc., can be usedas the output equipment.

Furthermore, in the embodiments described above, the lens 9 is alenticular lens having a convex portion turned toward the user side,however, the invention is not limited thereto, and for example, afry-eye lens can be used as long as it can display a virtual image onthe position of the tip of the pen as described above, and the lensshape is not especially limited. In place of the lenticular lens, it isalso possible that a parallax barrier is disposed between the liquidcrystal panel 3 a and the back light 8 so that the orientations of lightoutgoing from pixels are controlled to distribute light from the pixelsto the image for the right eye and the image for the left eye. Inaddition, for example, even when the tablet 2 and the lens 9 aredisposed between the polarizing film 10 and the color filter substrate6, the identical effects as those of the embodiments are obtained.

Furthermore, it is also possible that a liquid crystal panel thatresponds at a high speed and a back light that distributes the outgoinglight direction at a high speed are used, the image for the right eyeand the image for the left eye are alternately displayed by the liquidcrystal panel, and in synch with this, the back light distributes thelight outgoing direction, whereby the image for the right eye issupplied to the right eye of the user when the liquid crystal paneldisplays the image for the right eye and the image for the left eye issupplied to the left eye of the user when the liquid crystal paneldisplays the image for the left eye. In this case, the loci of two lightrays displaying the image for the right eye and the image for the lefteye corresponding to each other are also made to intersect with eachother at a point positioned on the front face of the input and outputdevice. Thereby, the user can recognize a virtual display surface as inthe case of the embodiments due to the persistence of vision of theeyes.

Moreover, in the embodiments, the input and output device is installedin a PDA or a mobile terminal, however, the invention is not limited tothese, and the input and output device of each embodiment describedabove can be installed in a cell phone, a game machine, a digitalcamera, or a digital video camera. It can also be used as a terminaldevice of a personal computer.

1. An input and output device comprising: a display unit including aplurality of pixel groups aligned in a matrix, each of said pixel groupshaving a plurality of pixels, a first pixel in said plurality of pixelsin a first pixel group and a second pixel in said plurality of pixels ina second pixel group displaying identical images simultaneously, saidfirst pixel and said second pixel positioned apart from each other via athird pixel, said third pixel being in said plurality of pixels ineither the first pixel group or the second pixel group; a flat inputunit; and an optical member which turns light outgoing from said firstpixel among the pixels belonging to each of said pixel groups toward afirst direction and turns light outgoing from said second pixel amongsaid pixels belonging to each of said pixel groups toward a seconddirection, and a locus of a first light outgoing from said first pixeland a locus of a second light outgoing from said second pixel which aredriven by the same signal intersect with each other on a front face ofsaid flat input unit; wherein said flat input unit is disposed in frontof said display unit and transmits light outgoing from said display unitand detects the coordinates of a contact point when said flat input unitis contacted from the front face.
 2. The input and output deviceaccording to claim 1, wherein the display unit includes a plurality ofthe first pixels and a plurality of the second pixels, and a first pixelgroup composed of the plurality of the first pixels and a second pixelgroup composed of the plurality of the second pixels display a sameimage.
 3. The input and output device according to claim 1, wherein inthe case of arrangement in which light outgoing from said first pixelreaches a right eye of an user and light outgoing from said second pixelreaches a left eye of the user, and the interval between the eyes of theuser is defined as W, the aligning pitch of said pixels in the directionof distributing light by said optical member is defined as P, thedistance from the display surface of said display unit to the front faceof said flat input unit is defined as T, the distance from the frontface of said flat input unit to the eyes of the user is defined as L,and an integer equal to or more than zero is defined as n, the followingformula is satisfied:W:L=P×(2n+1):T.
 4. The input and output device according to claim 1,wherein said display unit is a liquid crystal panel.
 5. The input andoutput device according to claim 1, wherein said flat input unit is atablet.
 6. The input and output device according to claim 1, whereinsaid optical member is a lenticular lens.
 7. The input and output deviceaccording to claim 1, wherein said optical member is a fry-eye lens. 8.The input and output device according to claim 1, wherein said opticalmember is a parallax barrier.
 9. The input and output device accordingto claim 1, wherein one picture element is composed of one of said pixelgroup or a plurality of said pixel groups disposed continuously, andsaid picture elements are disposed in a square region.
 10. An input andoutput device comprising: a light source for alternately emitting lightin a first direction and a second direction; a liquid crystal panel thatis disposed in front of said light source and includes a plurality ofpixel groups aligned in a matrix, each of said pixel groups having aplurality of pixels, a first pixel in said plurality of pixels in afirst pixel group and a second pixel in said plurality of pixels in asecond pixel group displaying identical images alternately, said firstpixel and said second pixel positioned apart from each other via a thirdpixel, said third pixel being in said plurality of pixels in either thefirst pixel group or the second pixel group; and a flat input unit thatis disposed in front of said liquid crystal panel and transmits lightoutgoing from said liquid crystal panel and detects the coordinates of acontact position when said flat input unit is contacted from a frontface, when said light source emits light in said first direction throughan optical member, said first pixel of said liquid crystal panel whichis driven by one signal transmits a light ray passing through a point ofthe front face of said flat input unit, and when said light source emitslight in the second direction through said optical member, said secondpixel of said liquid crystal panel which is driven by the same signal assaid one signal transmits a light ray passing through said point of thefront face of said flat input unit.
 11. An input and output deviceaccording to claim 1, wherein said input and output device is includedin a terminal device.
 12. An input and output device according to claim11, wherein said terminal device is a cell phone, a PDA, a mobileterminal, a game machine, a digital camera, or a digital video camera.13. An input and output device according to claim 10, wherein said inputand output device is included in a terminal device.
 14. An input andoutput device according to claim 13, wherein said terminal device is acell phone, a PDA, a mobile terminal, a game machine, a digital camera,or a digital video camera.